Yarn tensioning device



Feb. 22, 1949. E. RICHTER YARN TENSIONING DEVICE 2 Sheets-Sheet 1 Filed D80. 29, 1945 Inventor Emu. RICHTER E. RICHTER YARN TENSIONING DEVICE Feb. 22,1949.

Filed Dec. 29, 1945 2 Sheets-Sheet 2 r m w Emu. RICHTER Patented Feb 22, 1949 UNITED STATES PATENT OFFICE- YARN TENSIONING DEVICE Emil Richter, Philadelphia, Pa. Application December 29, 1945, Serial No. 638,175

This invention relates to improvements in knitting machines and more particularly to an improved yarn tensioning device for insuring even tension of the-yarn as it is laid across the noses of the sinkers and dividers of the knitting machines.

As is well appreciated in the knitting art, particularly in the full-fashioned hosiery art, correct'yarn tension is an important factor in the production of loops of uniform size and shape and in the formation of a satisfactory selvedge along the longitudinal edge of the stock ing blank. It frequently occurs that during the process of knitting the stocking fabric, the tension of the yarn is so disturbed as to result not only in the production of an irregularly formed selvedge, but also in the dropping of the loops from the narrowing points during the narrowing operation with consequent spoilage of the knitted fabric.

Moreover, in order to overcome the natural tendency of the yarn to curl and twist to form what are known as snarls in the yarn, it is necessary to maintain the yarn under proper tension, else the knitted fabric will be so unsightly that it must be rejected as irregular.

It is among the objects of the present invention to provide a yarn tensioning mechanism vwhich obviates the aforementioned difiiculties,

which insures the constant maintenance upon the yarn of the requisite'tension, and which automatically takes up the slack in the yarn whenever the knitting operation is interrupted.

In addition, it is a further object of the present invention to provide a simple and effective yarn tensioning device which Isreadily installed upon the knitting machine to operate either in conjunction with or in lieu of the conventional snapper and which is designed for convenient installation upon the snapper shaft itself or upon any other accessible part of the knitting machine frarne for operation with or without cam action.

Still another object of the present invention is to provide a yarn tensioning mechanism of the character aforesaid which is adjustable for a :Qlaims. (or. 242-154) cation and relative arrangement of parts, all as will appear more fully hereinafter, as shown in the accompanying drawings, and as finally ent invention:

Figure 2 is a side elevational view of the yarn tensioning device per se, showing the relative position of its parts when the knitting operation is interrupted;

Figure 3 is a view similar to Figure 2 but showing the condition of the tensioning device when the yarn drawn therethrough is under tension;

Figure 4 is a perspective view of the tensioning device in its condition as shown in Figure 2;

varying the tension imposed by it upon the yarn and which is designed to accommodate various types and weights of yams without imposing any interference or drag upon the same as they are fed into the knitting head of the machine.

Other objects and advantages of the invention will appear more fully hereinafter, it being understood that the present invention consists substantially in the combination, construction, lo-

Figure 5 is a front elevational view of'the device;

Figure 6 is a sectional view thereof taken on the line 6-6 of Figure 1;

Figure '7 is a side elevational view of a modifled construction of the tensioning device; and

Figures 8 and 9 are front and rear elevational views, respectively, of the modified form of the device.

Referring now to the drawings, and more particularly to Figure 1 thereof, it will be observed that the yarn tensioning mechanism of the present invention, designated generally by the reference numeral I0, is shown incorporated in a knitting machine of which .only so much is illustrated as is deemed necessary for a clear understanding of the construction and operation of the present invention. It will be understood, of course, that the yarn tensioning mechanism of the present invention may be incorporated in any of the conventional knitting machines, it being particularly adapted for installation in and as part of the fiat-bed full-fashioned type machine used in the production of full-fashioned hosiery. These knitting machines are usually provided with yam-tensioning devices suitably located between the source of yarn supply and the knitting head of the machine, and generally embody an intermittently operated yarn tensioner, commonly known as a snapper, with operating cams for automatically actuating the snappers to provide for proper tensioning of the yarn while the yarn carriers are being moved across the knitting field, particularly during the narrowing operations.

The snapp rs heretofore employed as yarn tensioners have been in the form of cast metal elements fitted with porcelain eyes and having operatively associated therewith leaf springs which press upon the yarn as the latter passes through the porcelain eyes, to thereby produce the required yarn tension. In addition, these conventional snappers normally have operatively associated therewith a ring tension device generally embodying a ring loosely fitted upon a vertically disposed rod or holder therefor in such manner that when the yarn was projected through the ring the latter was free to drop by gravity along its supporting rodto take up the slack between the source of yarn supply and the snapper.

The yarn tensioning device of the presentinvention eliminates these snappers, their operating cams and the ring tension assembly and in their stead provides an exceedingly simple and inexpensive mechanism which is automatically self-operative to insure maintenance of a constant pre-adjusted tension upon the yarn at the same time that it operates automatically to take up the slack in the yarn as it is delivered to the knitting head of the machine.

As has been indicated hereinbefore, the yarn tensioner of the present invention may be employed in lieu of the conventional cam-actuated snapper and its associated parts, or it may be employed in conjunction therewith. 'I'hus, Figures 2 to 6, inclusive show a form of the tensioner which is adapted to be mounted upon the snapper shaft in place of the snappers normally fitted thereon, while Figures '7 to 9 show a modified form of the tensioner adapted for mounting upon any suitable fixed part of the machine frame for operation in association with or independently of the conventional snappers. In all essential respects, both forms of the yarn tensioner are similar in principle and in operation, as will presently appear.

Referring now to Figures 2 to 6, inclusive, it will be observed that the yarn tensioning device as therein illustrated includes a main body member II, which may be cast or otherwise formed in the shape shown, having a rear part I! transversely notched, as at ll, to facilitate its mounting upon the snapper shaft it of the knitting machine, the lower member it of the notched aboutits longitudinal axis, is free I toward and away from theupper fixed coil II.

4 volutions thereof spaced well apart. It will be observed that these coils are so mounted relatively to each other that while their longitudinal axes lie in a common vertical plane, the lower coil 24 is shiftable relatively to the upper coil ll, which latter is fixedly supported in position with its opposite ends abutting the spaced. parallel parts it and 20 of the coil supporting member l2. Preferably, the upper coil 2! is of a length such that when its opposite ends are fitted over the poreclain eyes It and 22, it is under sufficient compression to frictionally maintain it in position between its end abutments II and II. To

prevent rotation of the coil 2! about its longitudinal axis, the rear end of the coil is provided with a laterally extending terminal end 26 which is extended upwardly through a hole 21 formed ix; the top part I. of the coil supporting member i The lower coil 24 is of somewhat shorter length than the upper coil and is provided at its opposite extremities with oppositely projecting terminal ends 28 and 2! adapted to loosely project through holes "and II respectively formed in the parts it and 23 of the supporting member. ,Thus, the lower coil 24, while restrained against rotation to shift bodily the convolutions of the two coilsbeing relatively such that the convolutions of one coil respectively may nest within order to eliminate any possibility of-jinterference between convolutions of the juxtaposed coils such part being fitted with a set screw I! to securely lock the device upon the shaft. Integral with the part I3 is an upwardly extending part l8, from which forwardly extends atop part is terminating at its forward extremity in a depending part 20 disposed in spaced, parallel relation to the rear part II. The parallel parts It and 20 of the body member I2 are disposed vertically above the shaft-engaging notched part l3 and are respectively provided with axially alined porcelain eyes 2| and 22, the arrangement being such that the yarn a to be delivered to the .knitting head of the machine from its source of supply I) (see Figure 1) may pass freely through the tensioning device without interference by the snapper shaft or the mounting part of the device. In addition to the parts just described, the main body member l2 of the tensioner also includes as an integral part thereof a forwardly extending shoulder element 23 located immediately adjacent to the rear part It and in vertically spaced as would prevent free movement of the movable coil 24 with respect to the fixed coil 1!. the convolutions of the two coils are spirallywound in opposite directions. Iv I As clearly appears in the drawings the terminal ends 28 and 28 of the lover coil are of sufficient length to guide and .retain the latter within its support throughout the fullextent of its permissible movement relatively to the fixed coil, the terminal end 2! being fitted'with a friction clip 32 which serves as a stop to limit downward displacement of the coil 24. By posltionally adjusting this clip along the terminal endll of the coil 24, the extent to which the, latter-may shift away from the fixed coil may be readily adjusted. It will be noted, of course, that for vall positions of the movable coil 24 relatively to the fixed coil, the longitudinal axes of the two coils are always parallel and in the same vertical plane.:

The modified form of the tensioner shown in Figures 7 to 9 differs from that hereinbefore described only in respect to the means employed for mounting the coil-supporting member II in fixed operative position upon the frame of the knitting machine. It will be observed that in this modified form of the coil supporting member, it is provided with a rearwardly extending lug or boss 33 which is adapted to .extend over and rest upon the bar'll' or other such fixed frame element of the knitting machine, such a bar being shown, for example, in Figure l. A clamping plate 35 is secured, as shown, :to the member I! by means of the screws 16-48, the organization being such that the supporting bar 34 is clamped between the member 12! and its clamping plate 35 to secureithe formerv in fixed rlgidposltion. I g I, i I

It will be understood, of course. that a tensioning device of the present inventionis employed in conjunction-with each yarn carrier of the the spaces formed between the proximate convolutions of the other coil. In

knitting machine, the yarn being delivered from its source of supply to and through the tensloner and thence to the yarn carrier. In threading the yarn through the coiled wire elements 24 and of the tensioner, the coil 24 is shifted vertically toward the fixed coil 25 sothat the convolutions of one coil overlap or nest with the convolutions of the other with the result that the bores of the two coils are brought into substantial registry. The yarn may then be threaded commonly through the two coils, so that upon release of the lower coil it drops of its own Weight into the position shown in Figure 2, with the result that the yarn is interlaced between the proximate convolutions of the then separated coils 24 and 25. It will be apparent that when the coil l2 drops into itslowered position, slack in the yarn between the delivery or forward end of the coil 25 and the knitting head of the machine is immediately taken up, this slack occurring usually when the knitting operation is interrupted. Upon resumption of the knitting operation, the pull of the yarn through the coils 24 and 25 tends to straighten out the yarn and so lifts the lower coil 24 into partial registry with the fixed upper coil 25, as shown in Figures 3 and 7.

It will be noted that the coil 24 is freely movable in its entirety with respect to the upper coil 25, and that the full weight of the lower coil is so suspended from the upper coil by the length of the yarn interlaced therebetween that it, in effect, floats upon the yarn. Accordingly,

successive portions of the yarn, as they traverse the coils 24 and 25, are constantly and uniformly subjected to positive tensions, which tend to straighten out and smooth the yarn free of all such curls and twists as might result in the formation of snarls during the knitting operation. Further, by positionally adjusting the friction clip 32 on the terminal end 28 of the lower movable coil 26, the degree of permissible displacement of latter with respect to the fixed coil 25 may be varied to provide for greater or lesser take-up of slack and more or less tension on the yarn as may be desired.

' It will be understood, of course, that the present invention is susceptible of various changes and modifications without departing from the general principles or real spirit thereof, and it is accordingly intended to claim the same broadly as well as specifically, as indicated by the appended claims.

What is claimed as new and useful is:

1. A yarn tensioning device of the character described comprising, in combination, a pair of open-coiled members adapted to be relatively shifted to present the convolutions of said members in interjacent relation to thereby provide a common passage therethrough for a length of yarn, and a mounting bracket for supporting one of said coils in fixed position, said bracket including means for guiding the other of said coils for movement in a plane common to the axes of both coils, said movable coil being suspended from said yarn with its axis paralleling that of the fixed coil.

2. A yarn tensioning device or the character described comprising, in combination, a relatively fixed open-coiled member, a second open-coiled member operatively associated with said fixed member and adapted to shift in a plane common to the axis of both members whereby to present the convolutions thereof in interjacent relation 3. A yarn tensioning device of the characterdescribed comprising, in combination, a rela-' tively fixed open-coiled member, a second opencoiled member operatively associated with said fixed member and adapted to shift in a plane common to the axis of both members whereby to present the convolutions thereof in interjacent relation to permit the passage of a length of yarn therethrough, and means operative to guide said shiftable member in its movement toward and away from said fixed member while maintaining its axis parallel to that of said fixed member, said shiftable member being freely suspended in its entirety from the yarn passing through the bore of said fixed member in such manner that the yarn traverses a sinuous path through the interjacent convolutions of said operatively associated members.

4. A yarn tensioning device of the character described comprising, in combination, a relatively fixed open-coiled member, a second open-coiled member operatively associated with said fixed member and adapted to shift in a plane common to the axis of both members whereby to present the convolutions thereof. in interjacent relation to permit the passage of a length of yarn therethrough, and means operative to. guide said shiftable member in its movement toward and away from said fixed member while maintaining its axis parallel to that of said fixed member, said shiftable member being freely suspended in its entirety from the yarn passing through the bore of said fixed member in suchmanner that the yarn traverses a sinuous path through the interjacent convolutions of said operatively associated members, the amplitude of said sinuous path of travel of the yarn varying in accordance with changes in the tension or pull upon the yarn as it passes through said members.

5. A yarn tensioning device of the character described comprising, in combination, a relatively fixed open-coiled member, a second opencoiled member operatively associated with said fixed member and adapted to shift in a plane common to the axis of both members whereby to present the convolutions thereof in interjacent relation to permit the passage of a length ofv yarn therethrough, and means operative to guide said shiftable member in its movement toward and away from said fixed member while maintaining its axis parallel to that of said fixed member, said shiftable member being freely suspended in its entirety from the yarn passing through the bore of said fixed member whereby said shiftable member, of its own weight, operates to draw successive portions of the yarn laterally of the fixed member to an extent suflicient to absorb any slack in the yarn.

6. In a yarn tensioning device of the character defined in claim 1 wherein the convolutions of said members are oppositely wound to permit said convolutions to be freely brought into or out of interjacent relation as the pull on the yarn delivered through said members is increased or decreased.

7. In a yarn tensioning device of the character defined in claim 1 wherein means is provided for adjustably limiting the extent of maximum displacement of the members relatively to each other.

provided with oppositely directed terminal extensions which coact with said support to maintain the axis of said shittable member parallel with that of the fixed member.

mm. RICHTER.

nsrr-zasncns orrrm The following references are of record in the tile of this patent:

UNITED STATI'B PATENTS Number Name Date 641,732 Schweiter Jan. 23, 1900 2,209,398 7 Garrett July 30, 1940 2,245,490 McHale June 10, 1941 

